This study aims to determine the changes in the cognitive structures of the 35 participants after ecology-based nature education in Bursa Uludag and its vicinity. This study used a single group pretest-posttest experimental mode where the data was collected by a word association test. It included the key concepts of nature, national parks, biodiversity, ecosystem, and environmental problems. The analyzed data determined that ecology-based nature education strengthened the cognitive structures of the participants regarding the key concepts. It was also concluded that the participant's awareness of the destruction of nature and the importance of nature protection had increased. The research results show that such education programs, providing one-to-one interaction with nature, help participants to understand nature and natural holistic cycles correctly, thus encouraging its protection.